The following abbreviations are herewith expanded, at least some of which are referred to within the following description of the state-of-the-art and the present invention.
CPE Customer Premises Device
ISM Intelligent Splitter Monitor
NA Network Analyzer
OLT Optical Line Termination
OMM Optical Monitoring Module
ONT Optical Network Terminal
ONU Optical Network Unit
PIC Photonic Integrated Circuitry
PLOAM Physical Layer Operations, Administration, and Maintenance
Many optical communication networks use a point to multipoint topology, for example a PON (passive optical network). In one example, a PON includes an OLT (optical line terminal) located in a CO (central office) that connects with a downstream optical splitter, which is usually remote from the CO, via a feeder fiber. The optical splitter in turn connects with a number of PON end devices such as ONUs (optical network units) via a corresponding number of access fibers. An optical splitter may also connect at one or more of its downstream ports to another optical splitter instead of an end device creating a cascaded topology. Similar topologies may be used for optical networks in other implementations, for example data centers.
In a PON, downstream transmissions from the OLT pass through the one or more optical splitters to the ONUs or other end devices. In most cases each end device receives the same transmission and extracts the portion intended for it. Upstream transmissions from the end devices, in a PON sometimes referred to as CPEs (customer premises equipment), use the same fiber and splitter path as downstream transmissions.
An ISM (intelligent splitter monitor) may be installed in the optical network. In a typical configuration, the downstream ports of one or more optical splitters are monitored to determine when an upstream transmission has arrived at a specific port. This may be facilitated by, for example, a tap coupling on the fiber or other communication channel connected at the downstream optical-splitter port. Downstream transmissions may be similarly monitored as well, although presently this is considered unnecessary.
Note that the techniques or schemes described herein as existing or possible are presented as background for the present invention, but no admission is made thereby that these techniques and schemes were heretofore commercialized, or known to others besides the inventors.